Photoperiod, Temperature, and the Interval from Sowing to Tassel Initiation in Diverse Cultivars of Maize

Abstract

Photoperiod and temperature influence the time from sowing to tassel initiation (TI) in maize (Zea mays L.), with appreciable genetic differences in relative sensitivity to these factors. Three experiments were run to examine these photothermal responses and genetic differences within 12 diverse cultivars chosen to represent germplasm adapted to temperate, tropical highland, tropical lowland, and subtropical environments. Photoperiod influenced the rate of progress toward TI in all cultivars (P < 0.05), with a threefold differences in sensitivity among them. In three of the more photoperiod‐sensitive cultivars (all adapted to the tropics or sub tropics), the value of the critical photoperiod, above which progress to TI is delayed by increase in photoperiod, was close to 13 h d−1. Temperature also influenced rate of progress toward TI. For many cultivars the optimum temperature (To) for rate of progress towards TI was appreciably cooler than the range from 30 to 34 °C that is generally assumed to apply throughout development from sowing to anthesis in maize; estimated values of To in a 12‐h photoperiod (Exp. 3) varied from 19 to 22 °C in the tropical highland cultivar H‐32 to 31 °C in the tropical lowland cultivar Tuxpeño Crema I Cycle 18. In the five cultivars examined, inherent earliness (i.e., time taken to TI in optimum environments) was almost identical, despite considerable differences in To, while relations between rate of progress to TI and suboptimal temperatures were curvilinear, with similar base values (mean 9.4 °C). Curvilinear relations were also detected at supraoptimal temperatures in three of the five cultivars. Curvilinearity in each of these relations (in contrast with the linear relations reported in many other crops) may be compatible with symptoms of damage to maize plants exposed continuously to extreme temperatures (e.g., 12 and 37 °C).

Hallauer’s Tusón: a decade of selection for tropical-to-temperate phenological adaptation in maize

“…Genetically, different allele frequency-dependent models could be invoked to hypothesize on the dynamics of change in this latter phase of selection (for example, with respect to increasing variance: Goodnight, 1988), and ongoing analysis using genotype data will hopefully permit such inference. However, at the level of the whole genotype (individual), variation in temperature-dependent flowering time has been noted for maize across the range of temperatures that occurred in the environments of the present study (Ellis et al, 1992), and analysis of environmental variables associated with gEI in this study revealed adaptation to low temperature as a relevant factor (Figure 6).…”

“…Other mechanisms such as response to temperature, which varies among maize germplasm sources (Ellis et al, 1992), are also thought to be important. Thus, photoperiod insensitivity is required but not sufficient to alleviate the spectrum of symptoms associated with the poor adaptation of tropical germplasm to temperate environments.…”

Disruption of Maize Kernel Growth and Development by Heat Stress (Role of Cytokinin/Abscisic Acid Balance)

“…High-temperature stress is documented to have detrimental effects on plant growth (Wamngton and Kanemíisu, 1983) and events involved in the growth and develclpment of reproductive organs, such as tassel initiation and time of flowering (Ellis et al, 1992), pollination and fertilization (Dupuis and Dumas, 1990), pollen sterility (Saini and Aspinall, 1982). and rate and duration of endosperm cell division (Jones et (a]., 1985).…”

Phyllochron responds to acclimation to temperature and irradiance in maize

“…Genotypic variation was small or nonexistent for maize planted on the same date , Birch et al 1998a), but may be larger at high temperatures (Ellis et al 1992). Birch et al (1998a) found no differences in phyllochron among temperate and tropically-adapted maize hybrids grown at Gatton, southeastern Queensland, Australia.…”